The objective of this project is to elucidate a new nanopore single-molecule effect of carrier-guided nanopore dielectrophoresis and explore its application in selective capture and noise-free detection of cancer-derived microRNA biomarkers in clinical samples. Lung cancer early detection urgently needs non-invasive and cost-effective confirmatory tests. Lung cancer-derived circulating microRNAs are becoming potential biomarkers for lung cancer diagnosis and prognosis. We have developed a nanopore single molecule Counter for electric detection of microRNAs, offering a potential non-invasive tool for disease screening and diagnostics. However, translating a conceptual nanopore sensor into a clinically usable technology faces a big challenge due to the complexity of clinical samples (plasma nucleic acids extracts), which cause intensive contaminative signals that severely influence the target miRNA determination and cannot be eliminated by any current methods. We discovered a new nanopore effect, carrier-guided nanopore dielectrophoresis (CND). Using this effect, we for the first time devise an extremely useful approach for noise-free nucleic acids detection in clinical samples. This approach utilizes a carrier-probe to bind the target miRNA. Under a highly non- uniform electric field outside the nanopore entrance, only the miRNA*carrier-probe dipole is captured in the nanopore by a dielectrophoresis force, whereas all non-target nucleic acids without carrier-probe binding are rejected by the repulsive electrostatic force. Consequently only the signatures for the miRNA*carrier-probe complex can be identified; any interference signal originating from non-target species is completely eliminated. This discovery opens a new route to the selective capture and noise-free detection of any target nuclic acids in the complex mixture, representing a substantial step toward the nanopore clinical applications. In this project, we are motivated to 1) completely elucidate the CND effect, explore the target diversity, enhance the sensitivity; 2) establish a nanopore dielectrophoresis approach for single-nucleotide discrimination and a barcode approach for multiplex miRNA detection; 3) utilize nanopore dielectrophoresis mechanism to detect lung cancer-derived miRNAs biomarkers in patient samples. The success of this project will be a substantial contribution to nanoscience and biotechnology, and open an avenue to nanopore applications in medical diagnostics, biomarkers discovery and pathogen detection, as well as plant science and food engineering where rapid genetic detection is required. The long term vision is applying a robust, flexible nanopore device in solving life science problems.